Determining a reputation of a network entity

ABSTRACT

An example method can include monitoring a network to identify flows between nodes in the network. Once flows have been identified, the flows can be tagged and labelled according to the type of traffic they represent. If a flow represents malicious or otherwise undesirable traffic, it can be tagged accordingly. A request can then be made for a reputation score of an entity which can identify one or more nodes of the network.

RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. No. 15/132,086, filed on Apr. 18, 2016, which in turn, claims priority to U.S. Provisional Application No. 62/171,899, filed Jun. 5, 2015, both of which are incorporated herein by reference in their entirety.

TECHNICAL FIELD

The present technology pertains to network security and more specifically pertains to determining the reputation of elements of a network.

BACKGROUND

Network communications requires network entities (e.g., routers, switches, endpoint groups, endpoints, etc.) to trust one another. A misconfigured or malicious network entity, however, can disrupt the normal operation of the network. For example, such a network entity can unnecessarily consume network resources or launch an attack on other entities of the network. Identifying misconfigured or malicious network entities in real time can prove difficult for network systems and administrators. Oftentimes, a misconfigured or malicious network entity is identified a posteriori or after the fact when harmful network activity has already occurred and containment of the entire network or a significant portion of the network becomes the only remedy.

BRIEF DESCRIPTION OF THE FIGURES

In order to describe the manner in which the above-recited and other advantages and features of the disclosure can be obtained, a more particular description of the principles briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only example embodiments of the disclosure and are not therefore to be considered to be limiting of its scope, the principles herein are described and explained with additional specificity and detail through the use of the accompanying drawings in which:

FIG. 1 shows an example network traffic monitoring system according to some example embodiments;

FIG. 2 illustrates an example network environment according to some example embodiments;

FIG. 3 shows an example method according to various embodiments;

FIG. 4 shows an example reputation influence table; and

FIGS. 5A and 5B illustrate example system embodiments.

DESCRIPTION OF EXAMPLE EMBODIMENTS Overview

An approach for establishing trust within a network is to identify the trustworthiness or reputation of each entity of the network. Communications can flow between a pair of network entities if their respective reputations meet certain criteria or abide by established security policies. The present technology involves dynamically determining the reputation of a network entity based on analyzing real-time network conditions with respect to patterns of traffic known to be harmful to the network.

An example method can include monitoring a network to identify flows between nodes in the network. Once flows have been identified, the flows can be tagged and labelled according to the type of traffic they represent. If a flow represents malicious or otherwise undesirable traffic, it can be tagged accordingly. A request can then be made for a reputation score of an entity. The reputation score can be used, for example, to determine whether to continue communicating with the entity.

DETAILED DESCRIPTION

Various embodiments of the disclosure are discussed in detail below. While specific implementations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without parting from the spirit and scope of the disclosure.

The disclosed technology addresses the need in the art for determining a reputation of a network entity.

FIG. 1 shows an example network traffic monitoring system 100 according to some example embodiments. Network traffic monitoring system 100 can include configuration and image manager 102, sensors 104, external data sources 106, collectors 108, analytics module 110, policy engine 112, and presentation module 116. These modules may be implemented as hardware and/or software components. Although FIG. 1 illustrates an example configuration of the various components of network traffic monitoring system 100, those of skill in the art will understand that the components of network traffic monitoring system 100 or any system described herein can be configured in a number of different ways and can include any other type and number of components. For example, sensors 104 and collectors 108 can belong to one hardware and/or software module or multiple separate modules. Other modules can also be combined into fewer components and/or further divided into more components.

Configuration and image manager 102 can provision and maintain sensors 104. In some example embodiments, sensors 104 can reside within virtual machine images, and configuration and image manager 102 can be the component that also provisions virtual machine images.

Configuration and image manager 102 can configure and manage sensors 104. When a new virtual machine (VM) is instantiated or when an existing VM is migrated, configuration and image manager 102 can provision and configure a new sensor on the physical server hosting the VM. In some example embodiments configuration and image manager 102 can monitor the health of sensors 104. For instance, configuration and image manager 102 may request status updates or initiate tests. In some example embodiments, configuration and image manager 102 can also manage and provision the virtual machines themselves.

In some example embodiments, configuration and image manager 102 can verify and validate sensors 104. For example, sensors 104 can be provisioned a unique ID that is created using a one-way hash function of its basic input/output system (BIOS) universally unique identifier (UUID) and a secret key stored on configuration and image manager 102. This UUID can be a large number that is difficult for an imposter sensor to guess. In some example embodiments, configuration and image manager 102 can keep sensors 104 up to date by installing new versions of their software and applying patches. Configuration and image manager 102 can obtain these updates automatically from a local source or the Internet.

Sensors 104 can reside on nodes of a data center network (e.g., virtual partition, hypervisor, physical server, switch, router, gateway, other network device, other electronic device, etc.). In general, a virtual partition may be an instance of a virtual machine (VM) (e.g., VM 104 a), sandbox, container (e.g., container 104 c), or any other isolated environment that can have software operating within it. The software may include an operating system and application software. For software running within a virtual partition, the virtual partition may appear to be a distinct physical server. In some example embodiments, a hypervisor (e.g., hypervisor 104 b) may be a native or “bare metal” hypervisor that runs directly on hardware, but that may alternatively run under host software executing on hardware. Sensors 104 can monitor communications to and from the nodes and report on environmental data related to the nodes (e.g., node IDs, statuses, etc.). Sensors 104 can send their records over a high-speed connection to collectors 108 for storage. Sensors 104 can comprise a piece of software (e.g., running on a VM, container, virtual switch, hypervisor, physical server, or other device), an application-specific integrated circuit (ASIC) (e.g., a component of a switch, gateway, router, standalone packet monitor, or other network device including a packet capture (PCAP) module or similar technology), or an independent unit (e.g., a device connected to a network device's monitoring port or a device connected in series along a main trunk of a datacenter). It should be understood that various software and hardware configurations can be used as sensors 104. Sensors 104 can be lightweight, thereby minimally impeding normal traffic and compute resources in a datacenter. Sensors 104 can “sniff” packets being sent over its host network interface card (NIC) or individual processes can be configured to report traffic to sensors 104. This sensor structure allows for robust capture of granular (i.e., specific) network traffic data from each hop of data transmission.

As sensors 104 capture communications, they can continuously send network traffic data to collectors 108. The network traffic data can relate to a packet, a collection of packets, a flow, a group of flows, etc. The network traffic data can also include other details such as the VM BIOS ID, sensor ID, associated process ID, associated process name, process user name, sensor private key, geo-location of a sensor, environmental details, etc. The network traffic data can include information describing the communication on all layers of the Open Systems Interconnection (OSI) model. For example, the network traffic data can include signal strength (if applicable), source/destination media access control (MAC) address, source/destination internet protocol (IP) address, protocol, port number, encryption data, requesting process, a sample packet, etc.

In some example embodiments, sensors 104 can preprocess network traffic data before sending to collectors 108. For example, sensors 104 can remove extraneous or duplicative data or they can create a summary of the data (e.g., latency, packets and bytes sent per flow, flagged abnormal activity, etc.). In some example embodiments, sensors 104 can be configured to only capture certain types of connection information and disregard the rest. Because it can be overwhelming for a system to capture every packet in a network, in some example embodiments, sensors 104 can be configured to capture only a representative sample of packets (e.g., every 1,000th packet or other suitable sample rate).

Sensors 104 can send network traffic data to one or multiple collectors 108. In some example embodiments, sensors 104 can be assigned to a primary collector and a secondary collector. In other example embodiments, sensors 104 are not assigned a collector, but can determine an optimal collector through a discovery process. Sensors 104 can change where they send their network traffic data if their environments change, such as if a certain collector experiences failure or if a sensor is migrated to a new location and becomes closer to a different collector. In some example embodiments, sensors 104 can send different types of network traffic data to different collectors. For example, sensors 104 can send network traffic data related to one type of process to one collector and network traffic data related to another type of process to another collector.

Collectors 108 can serve as a repository for the data recorded by sensors 104. In some example embodiments, collectors 108 can be directly connected to a top of rack switch. In other example embodiments, collectors 108 can be located near an end of row switch. Collectors 108 can be located on or off premises. It will be appreciated that the placement of collectors 108 can be optimized according to various priorities such as network capacity, cost, and system responsiveness. In some example embodiments, data storage of collectors 108 is located in an in-memory database, such as dashDB by International Business Machines. This approach benefits from rapid random access speeds that typically are required for analytics software. Alternatively, collectors 108 can utilize solid state drives, disk drives, magnetic tape drives, or a combination of the foregoing according to cost, responsiveness, and size requirements. Collectors 108 can utilize various database structures such as a normalized relational database or NoSQL database.

In some example embodiments, collectors 108 may only serve as network storage for network traffic monitoring system 100. In other example embodiments, collectors 108 can organize, summarize, and preprocess data. For example, collectors 108 can tabulate how often packets of certain sizes or types are transmitted from different nodes of a data center. Collectors 108 can also characterize the traffic flows going to and from various nodes. In some example embodiments, collectors 108 can match packets based on sequence numbers, thus identifying traffic flows and connection links. In some example embodiments, collectors 108 can flag anomalous data. Because it would be inefficient to retain all data indefinitely, in some example embodiments, collectors 108 can periodically replace detailed network traffic flow data with consolidated summaries. In this manner, collectors 108 can retain a complete dataset describing one period (e.g., the past minute or other suitable period of time), with a smaller dataset of another period (e.g., the previous 2-10 minutes or other suitable period of time), and progressively consolidate network traffic flow data of other periods of time (e.g., day, week, month, year, etc.). By organizing, summarizing, and preprocessing the network traffic flow data, collectors 108 can help network traffic monitoring system 100 scale efficiently. Although collectors 108 are generally referred to herein in the plurality, it will be appreciated that collectors 108 can be implemented using a single machine, especially for smaller datacenters.

In some example embodiments, collectors 108 can receive data from external data sources 106, such as security reports, white-lists (106 a), IP watchlists (106 b), who is data (106 c), or out-of-band data, such as power status, temperature readings, etc.

In some example embodiments, network traffic monitoring system 100 can include a wide bandwidth connection between collectors 108 and analytics module 110. Analytics module 110 can include application dependency (ADM) module 160, reputation module 162, vulnerability module 164, malware detection module 166, etc., to accomplish various tasks with respect to the flow data collected by sensors 104 and stored in collectors 108. In some example embodiments, network traffic monitoring system 100 can automatically determine network topology. Using network traffic flow data captured by sensors 104, network traffic monitoring system 100 can determine the type of devices existing in the network (e.g., brand and model of switches, gateways, machines, etc.), physical locations (e.g., latitude and longitude, building, datacenter, room, row, rack, machine, etc.), interconnection type (e.g., 10 Gb Ethernet, fiber-optic, etc.), and network characteristics (e.g., bandwidth, latency, etc.). Automatically determining the network topology can assist with integration of network traffic monitoring system 100 within an already established datacenter. Furthermore, analytics module 110 can detect changes of network topology without the need of further configuration.

Analytics module 110 can determine dependencies of components within the network using ADM module 160. For example, if component A routinely sends data to component B but component B never sends data to component A, then analytics module 110 can determine that component B is dependent on component A, but A is likely not dependent on component B. If, however, component B also sends data to component A, then they are likely interdependent. These components can be processes, virtual machines, hypervisors, virtual local area networks (VLANs), etc. Once analytics module 110 has determined component dependencies, it can then form a component (“application”) dependency map. This map can be instructive when analytics module 110 attempts to determine a root cause of a failure (because failure of one component can cascade and cause failure of its dependent components). This map can also assist analytics module 110 when attempting to predict what will happen if a component is taken offline. Additionally, analytics module 110 can associate edges of an application dependency map with expected latency, bandwidth, etc. for that individual edge.

Analytics module 110 can establish patterns and norms for component behavior. For example, it can determine that certain processes (when functioning normally) will only send a certain amount of traffic to a certain VM using a small set of ports. Analytics module can establish these norms by analyzing individual components or by analyzing data coming from similar components (e.g., VMs with similar configurations) Similarly, analytics module 110 can determine expectations for network operations. For example, it can determine the expected latency between two components, the expected throughput of a component, response times of a component, typical packet sizes, traffic flow signatures, etc. In some example embodiments, analytics module 110 can combine its dependency map with pattern analysis to create reaction expectations. For example, if traffic increases with one component, other components may predictably increase traffic in response (or latency, compute time, etc.).

In some example embodiments, analytics module 110 can use machine learning techniques to identify security threats to a network using malware detection module 166. For example, malware detection module 166 can be provided with examples of network states corresponding to an attack and network states corresponding to normal operation. Malware detection module 166 can then analyze network traffic flow data to recognize when the network is under attack. In some example embodiments, the network can operate within a trusted environment for a time so that analytics module 110 can establish baseline normalcy. In some example embodiments, analytics module 110 can contain a database of norms and expectations for various components. This database can incorporate data from sources external to the network (e.g., external sources 106). Analytics module 110 can then create access policies for how components can interact using policy engine 112. In some example embodiments, policies can be established external to network traffic monitoring system 100 and policy engine 112 can detect the policies and incorporate them into analytics module 110. A network administrator can manually tweak the policies. Policies can dynamically change and be conditional on events. These policies can be enforced by the components depending on a network control scheme implemented by a network. Policy engine 112 can maintain these policies and receive user input to change the policies.

Policy engine 112 can configure analytics module 110 to establish or maintain network policies. For example, policy engine 112 may specify that certain machines should not intercommunicate or that certain ports are restricted. A network and security policy controller (not shown) can set the parameters of policy engine 112. In some example embodiments, policy engine 112 can be accessible via presentation module 116. In some example embodiments, policy engine 112 can include policy data 112. In some example embodiments, policy data 112 can include endpoint group (EPG) data 114, which can include the mapping of EPGs to IP addresses and/or MAC addresses. In some example embodiments, policy data 112 can include policies for handling data packets.

In some example embodiments, analytics module 110 can simulate changes in the network. For example, analytics module 110 can simulate what may result if a machine is taken offline, if a connection is severed, or if a new policy is implemented. This type of simulation can provide a network administrator with greater information on what policies to implement. In some example embodiments, the simulation may serve as a feedback loop for policies. For example, there can be a policy that if certain policies would affect certain services (as predicted by the simulation) those policies should not be implemented. Analytics module 110 can use simulations to discover vulnerabilities in the datacenter. In some example embodiments, analytics module 110 can determine which services and components will be affected by a change in policy. Analytics module 110 can then take necessary actions to prepare those services and components for the change. For example, it can send a notification to administrators of those services and components, it can initiate a migration of the components, it can shut the components down, etc.

In some example embodiments, analytics module 110 can supplement its analysis by initiating synthetic traffic flows and synthetic attacks on the datacenter. These artificial actions can assist analytics module 110 in gathering data to enhance its model. In some example embodiments, these synthetic flows and synthetic attacks are used to verify the integrity of sensors 104, collectors 108, and analytics module 110. Over time, components may occasionally exhibit anomalous behavior. Analytics module 110 can analyze the frequency and severity of the anomalous behavior to determine a reputation score for the component using reputation module 162. Analytics module 110 can use the reputation score of a component to selectively enforce policies. For example, if a component has a high reputation score, the component may be assigned a more permissive policy or more permissive policies; while if the component frequently violates (or attempts to violate) its relevant policy or policies, its reputation score may be lowered and the component may be subject to a stricter policy or stricter policies. Reputation module 162 can correlate observed reputation score with characteristics of a component. For example, a particular virtual machine with a particular configuration may be more prone to misconfiguration and receive a lower reputation score. When a new component is placed in the network, analytics module 110 can assign a starting reputation score similar to the scores of similarly configured components. The expected reputation score for a given component configuration can be sourced outside of the datacenter. A network administrator can be presented with expected reputation scores for various components before installation, thus assisting the network administrator in choosing components and configurations that will result in high reputation scores.

Some anomalous behavior can be indicative of a misconfigured component or a malicious attack. Certain attacks may be easy to detect if they originate outside of the datacenter, but can prove difficult to detect and isolate if they originate from within the datacenter. One such attack could be a distributed denial of service (DDOS) where a component or group of components attempt to overwhelm another component with spurious transmissions and requests. Detecting an attack or other anomalous network traffic can be accomplished by comparing the expected network conditions with actual network conditions. For example, if a traffic flow varies from its historical signature (packet size, transport control protocol header options, etc.) it may be an attack.

In some cases, a traffic flow may be expected to be reported by a sensor, but the sensor may fail to report it. This situation could be an indication that the sensor has failed or become compromised. By comparing the network traffic flow data from multiple sensors 104 spread throughout the datacenter, analytics module 110 can determine if a certain sensor is failing to report a particular traffic flow.

Presentation module 116 can include serving layer 118, authentication module 120, web front end 122, public alert module 124, and third party tools 126. In some example embodiments, presentation module 116 can provide an external interface for network monitoring system 100. Using presentation module 116, a network administrator, external software, etc. can receive data pertaining to network monitoring system 100 via a webpage, application programming interface (API), audiovisual queues, etc. In some example embodiments, presentation module 116 can preprocess and/or summarize data for external presentation. In some example embodiments, presentation module 116 can generate a webpage. As analytics module 110 processes network traffic flow data and generates analytic data, the analytic data may not be in a human-readable form or it may be too large for an administrator to navigate. Presentation module 116 can take the analytic data generated by analytics module 110 and further summarize, filter, and organize the analytic data as well as create intuitive presentations of the analytic data.

Serving layer 118 can be the interface between presentation module 116 and analytics module 110. As analytics module 110 generates reports, predictions, and conclusions, serving layer 118 can summarize, filter, and organize the information that comes from analytics module 110. In some example embodiments, serving layer 118 can also request raw data from a sensor or collector.

Web frontend 122 can connect with serving layer 118 to present the data from serving layer 118 in a webpage. For example, web frontend 122 can present the data in bar charts, core charts, tree maps, acyclic dependency maps, line graphs, tables, etc. Web frontend 122 can be configured to allow a user to “drill down” on information sets to get a filtered data representation specific to the item the user wishes to drill down to. For example, individual traffic flows, components, etc. Web frontend 122 can also be configured to allow a user to filter by search. This search filter can use natural language processing to analyze the user's input. There can be options to view data relative to the current second, minute, hour, day, etc. Web frontend 122 can allow a network administrator to view traffic flows, application dependency maps, network topology, etc.

In some example embodiments, web frontend 122 may be solely configured to present information. In other example embodiments, web frontend 122 can receive inputs from a network administrator to configure network traffic monitoring system 100 or components of the datacenter. These instructions can be passed through serving layer 118 to be sent to configuration and image manager 102 or policy engine 112. Authentication module 120 can verify the identity and privileges of users. In some example embodiments, authentication module 120 can grant network administrators different rights from other users according to established policies.

Public alert module 124 can identify network conditions that satisfy specified criteria and push alerts to third party tools 126. Public alert module 124 can use analytic data generated or accessible through analytics module 110. One example of third party tools 126 is a security information and event management system (SIEM). Third party tools 126 may retrieve information from serving layer 118 through an API and present the information according to the SIEM's user interfaces.

FIG. 2 illustrates an example network environment 200 according to some example embodiments. It should be understood that, for the network environment 100 and any environment discussed herein, there can be additional or fewer nodes, devices, links, networks, or components in similar or alternative configurations. Example embodiments with different numbers and/or types of clients, networks, nodes, cloud components, servers, software components, devices, virtual or physical resources, configurations, topologies, services, appliances, deployments, or network devices are also contemplated herein. Further, network environment 200 can include any number or type of resources, which can be accessed and utilized by clients or tenants. The illustrations and examples provided herein are for clarity and simplicity.

Network environment 200 can include network fabric 212, layer 2 (L2) network 206, layer 3 (L3) network 208, endpoints 210 a, 210 b, . . . , and 210 d (collectively, “204”). Network fabric 212 can include spine switches 202 a, 202 b, . . . , 202 n (collectively, “202”) connected to leaf switches 204 a, 204 b, 204 c, . . . , 204 n (collectively, “204”). Spine switches 202 can connect to leaf switches 204 in network fabric 212. Leaf switches 204 can include access ports (or non-fabric ports) and fabric ports. Fabric ports can provide uplinks to spine switches 202, while access ports can provide connectivity for devices, hosts, endpoints, VMs, or other electronic devices (e.g., endpoints 204), internal networks (e.g., L2 network 206), or external networks (e.g., L3 network 208).

Leaf switches 204 can reside at the edge of network fabric 212, and can thus represent the physical network edge. In some cases, leaf switches 204 can be top-of-rack switches configured according to a top-of-rack architecture. In other cases, leaf switches 204 can be aggregation switches in any particular topology, such as end-of-row or middle-of-row topologies. Leaf switches 204 can also represent aggregation switches, for example.

Network connectivity in network fabric 212 can flow through leaf switches 204. Here, leaf switches 204 can provide servers, resources, VMs, or other electronic devices (e.g., endpoints 210), internal networks (e.g., L2 network 206), or external networks (e.g., L3 network 208), access to network fabric 212, and can connect leaf switches 204 to each other. In some example embodiments, leaf switches 204 can connect endpoint groups (EPGs) to network fabric 212, internal networks (e.g., L2 network 206), and/or any external networks (e.g., L3 network 208). EPGs can be used in network environment 200 for mapping applications to the network. In particular, EPGs can use a grouping of application endpoints in the network to apply connectivity and policy to the group of applications. EPGs can act as a container for buckets or collections of applications, or application components, and tiers for implementing forwarding and policy logic. EPGs also allow separation of network policy, security, and forwarding from addressing by instead using logical application boundaries. For example, each EPG can connect to network fabric 212 via leaf switches 204.

Endpoints 210 can connect to network fabric 212 via leaf switches 204. For example, endpoints 210 a and 210 b can connect directly to leaf switch 204 a, which can connect endpoints 210 a and 210 b to network fabric 212 and/or any other one of leaf switches 204. Endpoints 210 c and 210 d can connect to leaf switch 204 b via L2 network 206. Endpoints 210 c and 210 d and L2 network 206 are examples of LANs. LANs can connect nodes over dedicated private communications links located in the same general physical location, such as a building or campus.

Wide area network (WAN) 212 can connect to leaf switches 204 c or 204 d via L3 network 208. WANs can connect geographically dispersed nodes over long-distance communications links, such as common carrier telephone lines, optical lightpaths, synchronous optical networks (SONET), or synchronous digital hierarchy (SDH) links. LANs and WANs can include layer 2 (L2) and/or layer 3 (L3) networks and endpoints.

The Internet is an example of a WAN that connects disparate networks throughout the world, providing global communication between nodes on various networks. The nodes typically communicate over the network by exchanging discrete frames or packets of data according to predefined protocols, such as the Transmission Control Protocol/Internet Protocol (TCP/IP). In this context, a protocol can refer to a set of rules defining how the nodes interact with each other. Computer networks may be further interconnected by an intermediate network node, such as a router, to extend the effective size of each network. Endpoints 210 can include any communication device or component, such as a computer, server, hypervisor, virtual machine, container, process (e.g., running on a virtual machine), switch, router, gateway, host, device, external network, etc. In some example embodiments, endpoints 210 can include a server, hypervisor, process, or switch configured with virtual tunnel endpoint (VTEP) functionality which connects an overlay network with network fabric 212. The overlay network may allow virtual networks to be created and layered over a physical network infrastructure. Overlay network protocols, such as Virtual Extensible LAN (VXLAN), Network Virtualization using Generic Routing Encapsulation (NVGRE), Network Virtualization Overlays (NVO3), and Stateless Transport Tunneling (STT), can provide a traffic encapsulation scheme which allows network traffic to be carried across L2 and L3 networks over a logical tunnel. Such logical tunnels can be originated and terminated through VTEPs. The overlay network can host physical devices, such as servers, applications, endpoint groups, virtual segments, virtual workloads, etc. In addition, endpoints 210 can host virtual workload(s), clusters, and applications or services, which can connect with network fabric 212 or any other device or network, including an internal or external network. For example, endpoints 210 can host, or connect to, a cluster of load balancers or an EPG of various applications.

Network environment 200 can also integrate a network traffic monitoring system, such as the one shown in FIG. 1. For example, as shown in FIG. 2, the network traffic monitoring system can include sensors 104 a, 104 b, . . . , 104 n (collectively, “104”), collectors 108 a, 108 b, . . . 108 n (collectively, “108”), and analytics module 110. In some example embodiments, spine switches 202 do not have sensors 104. Analytics module 110 can receive and process network traffic data collected by collectors 108 and detected by sensors 104 placed on nodes located throughout network environment 200. In some example embodiments, analytics module 110 can be implemented in an active-standby model to ensure high availability, with a first analytics module functioning in a primary role and a second analytics module functioning in a secondary role. If the first analytics module fails, the second analytics module can take over control. Although analytics module 110 is shown to be a standalone network appliance in FIG. 2, it will be appreciated that analytics module 110 can also be implemented as a VM image that can be distributed onto a VM, a cluster of VMs, a software as a service (SaaS), or other suitable distribution model in various other example embodiments. In some example embodiments, sensors 104 can run on endpoints 210, leaf switches 204, spine switches 202, in-between network elements (e.g., sensor 104 h), etc. In some example embodiments, leaf switches 204 can each have an associated collector 108. For example, if leaf switch 204 is a top of rack switch then each rack can contain an assigned collector 108.

Although network fabric 212 is illustrated and described herein as an example leaf-spine architecture, one of ordinary skill in the art will readily recognize that the subject technology can be implemented based on any network topology, including any data center or cloud network fabric. Indeed, other architectures, designs, infrastructures, and variations are contemplated herein. For example, the principles disclosed herein are applicable to topologies including three-tier (including core, aggregation, and access levels), fat tree, mesh, bus, hub and spoke, etc. It should be understood that sensors and collectors can be placed throughout the network as appropriate according to various architectures.

FIG. 3 shows an example method 300 according to various embodiments. Example method 300 can begin and monitor network traffic data for a plurality of nodes of a network (step 302). For example, sensors 104 around the network can report network traffic data and send reports to collectors 108 which can then send summary reports to analytics module 110. Example method 300 can continue and further include analyzing the network traffic data to classify a type of traffic for each flow of a plurality of flows (step 304). For example, analytics module 110 can compare network traffic flows to various known patterns of network traffic, and flag or label the flows according to a known type of traffic that best matches the flows. Types of traffic can include malicious traffic, DDoS attacks, Port Knocks, FIN Scans, Command and Control messages, Spoofs (such as MAC or IP address), benign traffic, blocked traffic (e.g., by an access control list or a firewall), etc. For example, a DDoS attack can include a myriad of packets flowing into one destination endpoint from an assortment of source endpoints or IP addresses within a short period of time. A port knock can include a source endpoint sequentially attempting connections on various closed ports on a destination endpoint; although the connections are rejected by the destination endpoint's firewall, malicious software running on the destination endpoint can detect the rejected connections and thereby receive a communication encoded in the attempts. Analytics module 110 can detect these and other patterns that are characteristic of known traffic patterns.

Analytics module 110 can additionally track other flow characteristics such as an associated endpoint (or endpoint group), port, location, or service that is associated with a flow type (e.g., a victim of an attack). Analytics module 110 can then increase the likelihood that that future traffic to the same endpoint, port, location, or service, is of the same type. For example, if a DDoS is conclusively determined to have attacked a certain VM, later traffic that would typically result in a low probability of being an attack can, in light of the prior attack, be given a higher rated probability of being an attack.

Analytics module 110 can analyze a flow's packet's content. For example, analytics module 110 can determine the size of the packet, determine any patterns within the content (e.g., if it is encrypted or if the content is a uniform string of data), or find specific data within the content (e.g., a known text string associated with malicious data). Analytics module 110 can determine, based on the packet header data and/or the packet content, an application associated with the packet and flow.

In some embodiments, traffic is logged in an event log. Each event in the event log can represent a flow that has been flagged or labelled according to a type of traffic. For example, a DDoS flow can be represented as a DDoS event in the event log. Other events can be included in the event log such as an administrator reset (of a node, machine, reputation score, etc.) or a period of time without a negative event. Flows (and events) can be tagged with various characteristics. The characteristics can include source and destination: address (e.g., MAC, IP, etc.), host, operating system, hypervisor, application, user, endpoint group, subnet, VLAN, template (e.g., the template used to instantiate the source or destination software), reporting sensor, etc. The characteristics can include type (as determined in step 304), timestamp, quantity (e.g., how much data has been sent for the flow or event), path (e.g., the path that the flow took through the network), etc.

Example method 300 can then include receiving, from a requestor, a request for a reputation score associated with one or more nodes of the network (step 306). The requestor can be an administrator or any component internal or external to network traffic monitoring system 100 (including, collectors 108, reputation module 162, analytics module 110, etc.). In some embodiments, the request is received via an application program interface (API). In some embodiments, the request specifies the one or more nodes of the network, alternatively, the request can specify a criteria and example method 300 can include matching the criteria to the one or more nodes. For example, the request can specify an entity or combination of entities such as a: user name, endpoint group, operating system, template, application, configuration, VLAN, pair of endpoints, pair of endpoint groups, an endpoint and an endpoint group, etc. The reputation score for a network entity can be calculated based on reputation scores of sub-entities. For example, if the network entity is a subnet, the reputation score can of the subnet can be the average of nodes that comprise the subnet. Example method 300 can then include matching the request with the one or more nodes.

Example method 300 can then include identifying the type of traffic for one or more flows associated with the one or more nodes (step 308). For example, a system performing example method 300 can identify one or more flows associated with the one or more nodes; after identifying the flows, the system can, using the analysis in step 304, identify types of traffic that are associated with the flows.

In some embodiments, steps 308 and 310 are combined such that the system performing example method 300 can identify only flows that also match the request. For example, if the request describes a pair of nodes, then the system can only use flows that are associated with both nodes. This can help identify nodes that are otherwise reputable but communications between them are of negative reputation (e.g., a command and control server to a node).

Example method 300 can include determining the reputation score associated with the one or more nodes based on the type of traffic for the one or more flows associated with the one or more nodes (step 310). For example, some types can decrease the reputation score while positive types can increase the reputation score. In some embodiments, where types are recorded as events, each individual event can affect the reputation score as a weight. In some embodiments, the more a type is identified, the more each individual type influences the reputation. For example, the first type can be disregarded while future events can have a greater effect. This can help identify persistent problems while ignoring one-time issues. In some embodiments, a type can have a delay factor that diminishes how much it affects the reputation score over time. A more recent type or event can have a full effect, while older events and types can have smaller effects. In some embodiments, a reset event can reset a reputation score (e.g., to overcome the effects from prior events).

Example method 300 can then include sending the reputation score to the requestor (step 312).

FIG. 4 shows an example reputation influence table 400. A flow can have a type associated with it (which can be determined in step 304); these types can carry weights which can be used when calculating the reputation scores of entities (user name, endpoint group, operating system, template, application, configuration, VLAN, pair of endpoints, pair of endpoint groups, an endpoint and an endpoint group, etc) as discussed with regards to FIG. 3. The value of a type or event can be added to the reputation score as well as the recovery factor times time since last occurrence of the type or event. An example equation can be:

Reputation=Σ_(i=1) ^(n)Value_(i)+(Recovery_(i)*[Time_(current)−Time_(i)])  Equation 1:

Where n can correspond to the number of types (that is, flows matching a certain type, also called “events”) that match the criteria of the request. Using the above equation and table 400, if there were a DDoS attack at time 3 and FIN Scans at time 1 and time 5, a port knock at time 10, and the current time is 10 then the reputation score can be calculated as follows:

DDoS: −0.08+0.001*(10−3)

FIN₁: −0.05+0.005*(10−1)

FIN₂: −0.05+0.005*(10−5)

Port Knock: −0.5+0.03*(10−10)

=−0.603

In some embodiments, if it is the first occurrence of a type (or event), then the first time occurrence value will be used for Value_(r) instead of the value. For example, if an entity is associated with two instances of Port Knocking, the first instance can have a value of “−0.1” (corresponding to the first time occurrence value) while the second can have a value of “−0.5”. It should be understood that other methods for forgiving the first offences while punishing later offenses are possible.

In some embodiments, when a specific type is substantially far back in time, its recovery factor might overcome its value. For example, according to FIG. 4, a UDP Flooding that is at least one time period in the past will have a recovery factor that outweighs its value. For example, a ceiling of zero can be used for negative types and a floor of zero can be used for positive types. This can prohibit negative types providing a positive effect on the reputation score. However, it should be understood that such limitation (a floor or ceiling of zero) can be optional and other schemes are possible as appropriate.

In some embodiments, the recovery factor can be zero, indicating that a type is unrecoverable and requires a manual reset to be overcome. For example, the type can be removed or a reset reputation type can occur as explained later.

In some embodiments, a reputation score can be influenced by determining the time that the entity being scored has been without a negative type. For example, in some embodiments, if the last negative type was at time 1 and it is currently at time 10, then 9 types of “no-negative types” can be triggered, resulting (after referencing example table 400) in an increase of 0.09 to the reputation score. In some embodiments, this no-negative types increase can be discarded after a negative type occurs. However, this can cause problems because a small negative type might undo a lengthy period of trustworthiness. Therefore, in some embodiments, these no-negative type types can persist despite later-occurring negative types.

In some embodiments, an entity can be associated with a reset reputation type. A reset reputation can nullify all preceding reputation types, thus bringing the reputation score back to an initial value such as zero.

Various applications of a reputation score are disclosed herein. For example a node can, before transmitting (or retransmitting) a flow, consult the network entity's reputation score to determine whether it should (or is allowed to) transmit the flow. In some embodiments, network traffic monitoring system 100 can use reputation scores to set access control lists (ACLs) or other network policy instruments (e.g., firewall configurations, Quality of Service priorities, VLAN assignment, etc.). Network traffic monitoring system 100 can use reputation scores to generate a network status report. The network status report can indicate network entities with low reputation scores and what events caused the low reputation scores. The network status report can suggest possible remedial measures to increase the reputation scores of such network entities.

Example reputation scores can be from −1 (untrustworthy) to +1 (trustworthy), from 0 to 100, a percentage of trustworthiness or untrustworthiness. A reputation score can also be a description of the level of trust (e.g., “trustworthy, “somewhat trustworthy”, “unknown”, “somewhat untrustworthy”, or “untrustworthy”). A reputation score can include a confidence score, represented by a variance or confidence interval. For example, a network entity that is definitively trustworthy (e.g., because it has been active on the network for an extended period of time) can have a low variance or confidence interval. In contrast, a network entity that is new or unknown can have a high variance or confidence interval to indicate that its associated reputation score likely is inaccurate.

FIG. 5A and FIG. 5B illustrate example system embodiments. The more appropriate embodiment will be apparent to those of ordinary skill in the art when practicing the present technology. Persons of ordinary skill in the art will also readily appreciate that other system embodiments are possible.

FIG. 5A illustrates a conventional system bus computing system architecture 500 wherein the components of the system are in electrical communication with each other using a bus 505. Example system 500 includes a processing unit (CPU or processor) 510 and a system bus 505 that couples various system components including the system memory 515, such as read only memory (ROM) 570 and random access memory (RAM) 575, to the processor 510. The system 500 can include a cache of high-speed memory connected directly with, in close proximity to, or integrated as part of the processor 510. The system 500 can copy data from the memory 515 and/or the storage device 530 to the cache 512 for quick access by the processor 510. In this way, the cache can provide a performance boost that avoids processor 510 delays while waiting for data. These and other modules can control or be configured to control the processor 510 to perform various actions. Other system memory 515 may be available for use as well. The memory 515 can include multiple different types of memory with different performance characteristics. The processor 510 can include any general purpose processor and a hardware module or software module, such as module 1 537, module 7 534, and module 3 536 stored in storage device 530, configured to control the processor 910 as well as a special-purpose processor where software instructions are incorporated into the actual processor design. The processor 510 may essentially be a completely self-contained computing system, containing multiple cores or processors, a bus, memory controller, cache, etc. A multi-core processor may be symmetric or asymmetric.

To enable user interaction with the computing device 500, an input device 545 can represent any number of input mechanisms, such as a microphone for speech, a touch-sensitive screen for gesture or graphical input, keyboard, mouse, motion input, speech and so forth. An output device 535 can also be one or more of a number of output mechanisms known to those of skill in the art. In some instances, multimodal systems can enable a user to provide multiple types of input to communicate with the computing device 500. The communications interface 540 can generally govern and manage the user input and system output. There is no restriction on operating on any particular hardware arrangement and therefore the basic features here may easily be substituted for improved hardware or firmware arrangements as they are developed.

Storage device 530 is a non-volatile memory and can be a hard disk or other types of computer readable media which can store data that are accessible by a computer, such as magnetic cassettes, flash memory cards, solid state memory devices, digital versatile disks, cartridges, random access memories (RAMs) 575, read only memory (ROM) 570, and hybrids thereof.

The storage device 530 can include software modules 537, 534, 536 for controlling the processor 510. Other hardware or software modules are contemplated. The storage device 530 can be connected to the system bus 505. In one aspect, a hardware module that performs a particular function can include the software component stored in a computer-readable medium in connection with the necessary hardware components, such as the processor 510, bus 505, display 535, and so forth, to carry out the function.

FIG. 5B illustrates an example computer system 550 having a chipset architecture that can be used in executing the described method and generating and displaying a graphical user interface (GUI). Computer system 550 is an example of computer hardware, software, and firmware that can be used to implement the disclosed technology. System 550 can include a processor 555, representative of any number of physically and/or logically distinct resources capable of executing software, firmware, and hardware configured to perform identified computations. Processor 555 can communicate with a chipset 560 that can control input to and output from processor 555. In this example, chipset 560 outputs information to output 565, such as a display, and can read and write information to storage device 570, which can include magnetic media, and solid state media, for example. Chipset 560 can also read data from and write data to RAM 575. A bridge 580 for interfacing with a variety of user interface components 585 can be provided for interfacing with chipset 560. Such user interface components 585 can include a keyboard, a microphone, touch detection and processing circuitry, a pointing device, such as a mouse, and so on. In general, inputs to system 550 can come from any of a variety of sources, machine generated and/or human generated.

Chipset 560 can also interface with one or more communication interfaces 590 that can have different physical interfaces. Such communication interfaces can include interfaces for wired and wireless local area networks, for broadband wireless networks, as well as personal area networks. Some applications of the methods for generating, displaying, and using the GUI disclosed herein can include receiving ordered datasets over the physical interface or be generated by the machine itself by processor 555 analyzing data stored in storage 570 or 575. Further, the machine can receive inputs from a user via user interface components 585 and execute appropriate functions, such as browsing functions by interpreting these inputs using processor 555.

It can be appreciated that example systems 500 and 550 can have more than one processor 510 or be part of a group or cluster of computing devices networked together to provide greater processing capability.

For clarity of explanation, in some instances the present technology may be presented as including individual functional blocks including functional blocks comprising devices, device components, steps or routines in a method embodied in software, or combinations of hardware and software.

In some embodiments the computer-readable storage devices, mediums, and memories can include a cable or wireless signal containing a bit stream and the like. However, when mentioned, non-transitory computer-readable storage media expressly exclude media such as energy, carrier signals, electromagnetic waves, and signals per se.

Methods according to the above-described examples can be implemented using computer-executable instructions that are stored or otherwise available from computer readable media. Such instructions can comprise, for example, instructions and data which cause or otherwise configure a general purpose computer, special purpose computer, or special purpose processing device to perform a certain function or group of functions. Portions of computer resources used can be accessible over a network. The computer executable instructions may be, for example, binaries, intermediate format instructions such as assembly language, firmware, or source code. Examples of computer-readable media that may be used to store instructions, information used, and/or information created during methods according to described examples include magnetic or optical disks, flash memory, USB devices provided with non-volatile memory, networked storage devices, and so on.

Devices implementing methods according to these disclosures can comprise hardware, firmware and/or software, and can take any of a variety of form factors. Typical examples of such form factors include laptops, smart phones, small form factor personal computers, personal digital assistants, rackmount devices, standalone devices, and so on. Functionality described herein also can be embodied in peripherals or add-in cards. Such functionality can also be implemented on a circuit board among different chips or different processes executing in a single device, by way of further example.

The instructions, media for conveying such instructions, computing resources for executing them, and other structures for supporting such computing resources are means for providing the functions described in these disclosures.

Although a variety of examples and other information was used to explain aspects within the scope of the appended claims, no limitation of the claims should be implied based on particular features or arrangements in such examples, as one of ordinary skill would be able to use these examples to derive a wide variety of implementations. Further and although some subject matter may have been described in language specific to examples of structural features and/or method steps, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to these described features or acts. For example, such functionality can be distributed differently or performed in components other than those identified herein. Rather, the described features and steps are disclosed as examples of components of systems and methods within the scope of the appended claims. Moreover, claim language reciting “at least one of” a set indicates that one member of the set or multiple members of the set satisfy the claim. 

1. A computer-implemented method, comprising: identifying a type of traffic for one or more flows associated with one or more nodes; determining a reputation score of one or more nodes based on the type of traffic through the one or more nodes; and blocking a node of the one or more nodes from sending traffic in response to the reputation score for that node being below a predetermined threshold; wherein the reputation score is calculated by: Reputation Score=Σ_(i=1) ^(n)Value_(i)+(Recovery_(i)*[Time_(current)−Time_(i)]) where: n is the number of events identified during the identifying; Value_(i) is an initial relative impact of the type of traffic of an ith event on the reputation score, where Value_(i) is different for at least two different values of i; Recovery_(i) is a constant for the type of traffic of the ith event, wherein the Recovery for at least one event is non-zero, and the recovery for at least one other event is zero; Time_(current) is a time value based on a current time; Time_(i) is a time value based on a time of the ith event.
 2. The computer-implemented method of claim 1, further comprising, before the determining, analyzing network traffic data to classify a type of traffic for each flow of a plurality of flows.
 3. The computer-implemented method of claim 2, wherein analyzing the network traffic data to classify a type of traffic for each flow includes: matching the flow to a known pattern of traffic.
 4. The computer-implemented method of claim 3, wherein the known pattern of traffic corresponds to at least one of a DDOS attack, a FIN scan, or a port knock.
 5. The computer-implemented method of claim 2, wherein analyzing the network traffic data to classify a type of traffic for each flow includes: identifying one or more network policies associated with the flow; and determining whether the flow complies with the one or more network policies.
 6. The computer-implemented method of claim 1, wherein the reputation score is associated with at least one of an endpoint, an endpoint group, a pair of endpoints, a pair of endpoint groups, an endpoint and an endpoint group, a user name for a process, a process, or a path for a process of a network.
 7. The computer-implemented method of claim 1, wherein determining the reputation score includes: determining at least one of the one or more flows is tagged as malicious or misconfigured; and decreasing the reputation score.
 8. A computer readable media storing instructions which when executed by a system cause the system to perform operations comprising: identifying a type of traffic for one or more flows associated with one or more nodes; determining a reputation score of one or more nodes based on the type of traffic through the one or more nodes; and blocking a node of the one or more nodes from sending traffic in response to the reputation score for that node being below a predetermined threshold; wherein the reputation score is calculated by: Reputation Score=Σ_(i=1) ^(n)Value_(i)+(Recovery_(i)*[Time_(current)−Time_(i)]) where: n is the number of events identified during the identifying; Value_(i) is an initial relative impact of the type of traffic of an ith event on the reputation score, where Value_(i) is different for at least two different values of i; Recovery_(i) is a constant for the type of traffic of the ith event, wherein the Recovery for at least one event is non-zero, and the recovery for at least one other event is zero; Time_(current) is a time value based on a current time; Time_(i) is a time value based on a time of the ith event.
 9. The media of claim 8, the operations further comprising, before the determining, analyzing network traffic data to classify a type of traffic for each flow of a plurality of flows.
 10. The media of claim 9, wherein analyzing network traffic data to classify a type of traffic for each flow includes: matching the flow to a known pattern of traffic.
 11. The media of claim 10, wherein the known pattern of traffic corresponds to at least one of a DDOS attack, a FIN scan, or a port knock.
 12. The media of claim 8, wherein analyzing network traffic data to classify a type of traffic for each flow includes: identifying one or more network policies associated with the flow; and determining whether the flow complies with the one or more network policies.
 13. The media of claim 8, wherein the reputation score is associated with at least one of an endpoint, an endpoint group, a pair of endpoints, a pair of endpoint groups, an endpoint and an endpoint group, a user name for a process, a process, or a path for a process of a network.
 14. The media of claim 8, wherein determining the reputation score includes: determining at least one of the one or more flows is tagged as malicious or misconfigured; and decreasing the reputation score.
 15. A system, comprising: a computer readable media storing instructions; a processor programmed to execute the instructions to perform operations comprising: identifying a type of traffic for one or more flows associated with one or more; determining a reputation score of one or more nodes based on the type of traffic through the one or more nodes; and blocking a node of the one or more nodes from sending traffic in response to the reputation score for that node being below a predetermined threshold; wherein the reputation score is calculated by: Reputation Score=Σ_(i=1) ^(n)Value_(i)+(Recovery_(i)*[Time_(current)−Time_(i)]) where: n is the number of events identified during the identifying; Value_(i) is an initial relative impact of the type of traffic of an ith event on the reputation score, where Value_(i) is different for at least two different values of i; Recovery_(i) is a constant for the type of traffic of the ith event, wherein the Recovery for at least one event is non-zero, and the recovery for at least one other event is zero; Time_(current) is a time value based on a current time; Time_(i) is a time value based on a time of the ith event.
 16. The system of claim 15, the operations further comprising, before the determining, analyzing network traffic data to classify a type of traffic for each flow of a plurality of flows.
 17. The system of claim 16, wherein analyzing the network traffic data to classify a type of traffic for each flow includes: matching the flow to a known pattern of traffic.
 18. The system of claim 17, wherein the known pattern of traffic corresponds to at least one of a DDOS attack, a FIN scan, or a port knock.
 19. The system of claim 16, wherein analyzing the network traffic data to classify a type of traffic for each flow includes: identifying one or more network policies associated with the flow; and determining whether the flow complies with the one or more network policies.
 20. The system of claim 15, wherein the reputation score is associated with at least one of an endpoint, an endpoint group, a pair of endpoints, a pair of endpoint groups, an endpoint and an endpoint group, a user name for a process, a process, or a path for a process of a network. 